How to Design a Tank Destroyer

greetings all i am going back to basics here i have been asked to explain the thinking of the open tops and light armor of american tank destroyers and why the u.s seemed to go its own way after all if you think of german or soviet tds you tend to think of close-top vehicles of greater armor yet of course one doesn't have to look far to realize that the americans were far from the only country to take the open-topped route so did they really go their own way so if you're going to go and make a tank destroyer and you want to make it to fit a doctrine how does the doctrine result in the characteristics of a tank destroyer that's more or less what i'm going to go over now the u.s of course was not the first country to conceptualize a tank destroyer probably the first country to really put mind to the problem was the country on the receiving end of things in world war one germany discussions on a special anti-tank gun called the tank avr canon or tac started february 1926 albeit as a towed carriage by may 1927 talk from the troopanompt which was the code name for the german general staff had moved towards mechanization either tax towed by motorized vehicles or directly mounted onto full tracked chassis exactly what the thing was supposed to look like the staff left for the engineers to figure out but one of the first examples provided was of a 3.7 centimeter gun on a commercial halimag tractor chassis 1927 the chef des herreras whatever the head of the army weapons development put out a statement that a class of vehicles named tank zur stormer loosely translated as tank destroyers were the most effective weapons against tanks these self-propelled guns should be of lowest possible height and maximum possible speed it was envisioned as a defensive weapon against enemy tank attacks though at the time the nimbleness was more for the sake of the tactical application against the enemy's tanks sides or rear though i have to say given the nature of the tanks has existed at the time that may not necessarily have been required that said the suggestion that a wheelcom contract may be a suitable alternative to a full track combined with the thought that a 12-gun battery per division would suffice seems to imply that the thinking was that they would be a bit more reactionary now this is merely interpretation on my part made with later knowledge though i mean to be clear also and this is a bit of a preview of events that we're going to have about a dozen years later the chief stated that traditional horse-drawn anti-tank guns wouldn't work because they either wouldn't be where they were needed or they would be so spread out that they will be overwhelmed by a concentrated attack ranges of up to two kilometers were expected now this by the way is coming from panzer tracks if you're curious development then started moving towards vehicles capable of mounting either an artillery piece as a self-propelled gun or a 3.7 pack gun a few prototypes were built including the light detractor which was a small enough vehicle that it could mount only the anti-tank gun it could however total along at 30 kilometers an hour which compared to tanks of the era wasn't really bad so there it sat for a while until late 1934 when two more programs were started to create panzer jaeger which were faster and more maneuverable than tanks so i'm now going to go into a long description of requirements quoted from the army's chief who use the term offensive tank defense which you will see again later on the american side and no quote begins the frequently expressed principle that the best defense against a tank is another tank is at least disputed bomber aircraft are not employed against heavy bomber aircraft and let's just ignore that thing from north africa instead a faster and more maneuverable fighter aircraft presenting a smaller target are used that only have to be armed in such a way that they can really damage a bomber at sea the torpedo boat is fought with a torpedo boat destroyer and a submarine with a submarine destroyer in both types of destroyers the most important specification is superior speed and maneuverability armored only as far as it doesn't interfere with both primary characteristics recently this train of thought by many sailors has reached its peak with the snow boot apparently against even the heaviest and largest warships the snowboat is a valuable and dangerous offensive weapon these very small targets have a considerable speed of about 40 knots and are therefore very difficult to hit armor is practically renounced they have fulfilled their role if they can get within effective torpedo firing range undamaged even if they are destroyed after achieving their task their employment is worthwhile even from a purely economic standpoint but after firing torpedoes they will frequently succeed in getting away thanks to the characteristics of high speed maneuverability in small target area the question remains whether a tank destroyer can be built exactly corresponding to the fighter aircraft torpedo boat destroyer submarine destroyer and especially the schnillbot in which armor is rejected in favor of the following primary characteristics very high road speed to achieve good operational mobility good cross-country mobility at least the same as a tank cross-country speed and maneuverability greatly superior to a tank small target area good firing platform for accurate shooting while stationary weapons capable of target destruction that ranges from 700 meters up cheap and quick mass production in comparison to tanks the high road speeds more than double that of a tank allows anti-tank units to be rapidly sent to threaten the sectors unquote so the idea is here we have a vehicle which is supposed to be small fast with a big gun cheap to make and optimized to kill tanks it doesn't specifically state it has to be open topped but a lack of roof does help with these characteristics so the vehicles that germans built next were open topped and these were half track based they were almost over twice the speed of a tank on road which the document stated allowed anti-tank units to be rapidly sent to threatened sectors now the designs varied from the standard 3.7 centimeter gun to a long barreled l70 and even a 7.5 centimeter l 40.8 the latter tube being designed with heavily armored french tanks in mind these smaller vehicles never entered service but two of a slightly later variant did in 1942 go to north africa to be used as bunker busters which is a common theme a number of german vehicles we consider to be tank destroyers were in fact designed to be bunker busters thus is the case for the 8.8 on the 12 ton half track as a result there was little emphasis on tactical or operational speed the open nature of this vehicle was simply more reflection of the weapon meanwhile over on the other side of the atlantic the americans are taking their own look at the problem a basic anti-tank doctrine issued 1936 was trialed in 1937 during field exercises by second division the director of the exercise and the chief of staff of second division at the time was a brigadier general leslie mcnair you may have heard of him the major conclusion was that the division needed to be reformed to be triangular but for anti-tank purposes not only would each regiment have their own anti-tank company but the division would have a mobile battalion equipped with its own recon units which could react to enemy threats the anti-mechanized defense would be in depth now they didn't have the equipment to do it yet not even towed 37 guns but they had the general idea the guns would eventually follow the us and germans though seem to be the only group really following this line of thinking the french were absolutely wedded to the toad anti-tank gun believing it to be the master of the tank attack like the machine gun proved to be against the infantryman in the great war they basically threw all their defenses to hold the line the question of what to do if the line failed was generally addressed in terms of a conventional unit counter move not one oriented to deal specifically with armored formations the background to that generally relates to the french thought on tanks operating without infantry and the ability of the granted very impressive french artillery to strip the enemy tanks of their infantry accompaniment and you can have a dig into it there's an article in the military review of may 1976 it's freely available online the polls were more willing to consider the concept of a tank fighting vehicle but didn't really have the resources to throw out the problem certainly not at depth level steve zeloga has done a little bit of writing on that it's also available online it would not be until early 1940 that the germans would return their attentions directly to the camp wagon abrar problem as they called it at that point the first of what we may today consider to be true tank destroyers in the american world war ii context was the panzer jaeger one the operational requirement was in effect to stop french tank attacks by heavily armored beasties such as the shar b1 if you look at their instructional manual it states that these schneller panzer jaeger are unique in their continual readiness to fire high cross-country mobility and armor protection they are therefore qualified to combat enemy tanks by attacking now one may wonder about this description but compared to the standard towed anti-tank gun it was still better in all three respects now here's an important line from the manual unhindered observation with an open top allows early recognition and engagement of enemy tanks which have limited vision it's the old c first shoot first hit first thing basis of issue was to be one battalion per division usually panzer division but one battalion per division it was expected that the unit would be employed by company but the manual does say that employment by battalion will be useful in many situations if you look at the tactics when the panzer division is on the defense or whatever division they're attached to the panzer jaegers are held in reserve and will not be sent into action until the direction of the enemy tank attack is identified the task is to destroy the enemy tanks which have penetrated into the battlefield when the unit is on the offense it has the primary task of securing the flanks in front against enemy tank attack the manual always talks about how the panzer jaegers engage attacking enemy tanks it says very little about enemy tanks which are not attacking even when they are directly supporting an attacking panzer brigade as a secondary function they can engage anti-tank guns and fortifications so if you see my u.s tank destroyer video this is all going to be very familiar to you just most of the above was originally written in german not in english in what would become fm 18-5 a month after the panzer jaeger manual was published that i just quoted you then have the oh crap moment of the fall of france when it was discovered that things like a doctrine of having an anti-tank gun for every 100 meters of frontage such as the french had was not going to be enough the british certainly aren't in a position to be able to come up with novel concepts they're just being stretched to build whatever they already had approved the americans though have the opportunity to chew upon this with something of a lesser time crunch by late 1940 it was concluded that a frontal defense wasn't going to work and the field service regulations of 1941 stated that they wanted to have a minimum of 80 guns up front and a maximum in a mobile reserve these are of course still all towed still though more mobile guns were required enter in mid 1941 a major raider meyer graduate of the kriegs academy but whether he was influenced by german anti-tank thought of the matter is unknown but he felt that the bulk of anti-tank units were to be pooled at higher headquarters in highly mobile centrally located groups by the way just to make it clear he's an american officer the primary weapon would be a mobile heavily gunned tank chaser so again we're talking speed and guns more than anything else due to the lack of any particular progress general marshall set up an anti-tank conference headed by then colonel bruce in july 1941. the description of the vehicle which they desired was fuss again quote we're after a fast-moving vehicle armed with a weapon with a powerful punch which can be easily and quickly fired and in the last analysis we would like to get armored protection against small arms fire so that this weapon cannot be put out by machine guns the idea that we have in mind is in reality similar to the battle cruiser its tactics in operating against the tanks the battleship and this analogy have to be different from the tactics which we had employed in operating the tank or battleship against the tank or battleship speed visibility and hitting power of the tank destroyer should compensate to some degree for its lack of armor unquote now by this point the army had started investigating the possibility of a self-propelled anti-tank gun with a number of wheeled carriages with a 37-mm gun however it was time to lay out official required characteristics in a more formal manner as opposed to just throwing designs at the wall to see what's stuck a requirement for a light tank destroyer was put out within two weeks by army g4 signed by a general twaddle they wanted a quote a self-propelled mount for the 37-millimeter anti-tank gun in a light highly mobile fast lightly armored cross-country vehicle having a low silhouette this vehicle must be capable of being manufactured by mass production methods at minimum cost then there was a whole slew of physical characteristics starting with again quote simple in design relatively cheap and capable of mass production due to use of standard automotive attractor parts this is a major requirement unquote armor protection was listed as protection against the 0.50 caliber at 250 yards and armored to be of sufficient height to give all-around protection to the gun crew when firing position top armor was specified as none long distance speed was to be greater than or equal to any of the light tanks on all grades and road with cross country speed equal to the m3 light there were a slew of other requirements but there's a development ones to this particular discussion two weeks later another characteristic she went out looking for a vehicle from 57 millimeters to three inch which may perhaps also be used in his assault gun quote there is a military requirement for a self-propelled vehicle capable of mounting a more formidable weapon than the 37-millimeter anti-tank gun it is visualized that this heavier type mount will be used primarily to reinforce the lighter vehicles g2 reports are continuously being received indicating the fallacy of sending expensive unarmored fighting vehicles to operate on the modern battlefield the use of a shield only is extremely ineffective according to our reports and all countries are increasing the area of armor on anti-tank and assault artillery weapons as in the case of large and expensive tanks this vehicle will not be produced in numbers comparable to the lighter type due to increased cost and the additional time required for manufacture again now by the way unquote again armor was not to be placed on the roof and it was to be high enough only to protect the men inside in the end the two vehicles would be the 37-millimeter gun motor carriage m6 and the 75-mm gun motor carriage m3 though contrary to the initial thinking the heavy caliber gun would be the primary vehicle and soon the folly of the 37 in any shape or form would be completely made clear and then the vehicle removed entirely so again the lack of a roof will not only lighten the weight but even go as far as to make the mount cheaper now around this time the british start playing around with porte mounts for the two pounder now these are simply a solution to a technical problem the wheels on the two pounder carriage apparently weren't sufficiently rugged to be bouncing around towed on the rough north african terrain officially they weren't to be fired from the back of the truck but in practice they often were the six-pounder deacon was built to be fired from the truck but that's something of a barge of a vehicle which didn't really last after north africa come 1942 american thinking on the matter is more or less as follows quote the destroyer's gun and mount don't have the tank's armor but its crew commands greater speed visibility maneuverability and at least equal firepower it can pick the time and place to deliver its punch and then hightail it to a new position to strike again another doctrinal term by the way hightail if i tried using that in the ile course or captain's career course it'd murder me but there's precedent one good tank destroyer can be produced for materially less than the cost of a tank and in far less time with less critical materials first would be the case for not only the m10 but also m36 and to a large extent the m18 which wasn't actually much cheaper than the tank but was certainly more more mobile faster and had more visibility the m18s kill rate by the end of the war is an indicator of the success of the vehicle of course the americans are now going all in on turrets and they are not entirely alone in doing so the germans are trying to figure out how to put their at guns in a 360 degree traverse mount as well such as on the rso or the waffentragers these are not proving particularly successful the rsos have too little protection to begin with and the martyr is rather more sort of an expedient spg hornets and nashuan however is a purpose-designed vehicle they gave up on the traverse to have armor on all sides but without the roof again ideal method of operation per an instruction sheet from late 1943. the sherrera panzer jaeger ab parillon hornissa is the mobile defense for the command to concentrate against enemy tank attacks employee is an ab tai lung or a company so again what they're doing is they're maintaining the function similar to u.s tank destroyers of the panzer javis before just supposedly a company level then the germans lost the plot a bit the first two vehicles which are considered as tank destroyers with heavy armor and a roof are ferdinand and eggplants are four but they actually don't really count because they were both developed as stronger shots and was an entirely different role indeed the egg panther also started its development in 1943 as an 8.8 centimeter assault gun before being turned into a medium panzer jaeger we're going to ignore jagdtiger as just plain idiocy around this time also the british are looking at making their own vehicles the ideal one also has an open-topped traversing turret and this would be avenger in the meantime the sp valentine or also known as archer was built no turret but again an open top they are using m10s in the meantime the british though have a slightly different purpose in mind they are not reactionary tank destroyers in the german or the american sense of the concept they are in regiments mixed in with the toad guns and are literally self-propelled anti-tank guns much like the german rso with the pak-40 their advantage is in speed of emplacement and displacement so for example after the british secure an objective or at least they seize it an m10 can then drive forward and become an immediate self-replacing anti-tank foxhole after a while the towed guns can be in place to replace it so remember it would take 12 to 15 hours to properly in place a towed 17-pounder gun an m10 can be reasonably well in place in under an hour so why is the advantage of a turret well imagine you just moved into a position and have now spent time digging in maybe 12 to 15 hours and concealing the vehicle along the most likely enemy avenue of approach all is well if the enemy cooperates and comes at you from the front your expected route of advance a problem poses itself however if the enemy comes at you from the side requiring traversing the vehicle and all your camouflage falling off even if you dug in position have the space to turn in effect a platoon of turreted vehicles can engage as a group any targets in any direction more or less whereas a platoon of turretless vehicles are either forced to engage piecemeal with some guns unable to bear or the whole lot of them have to turn and then they lose their advantages of the prepared position now of course there is a disadvantage to not having a roof germans started to fall in love with mortars the soviets were very well in love with artillery as a whole to begin with and in love or not the british and the americans in particular are extremely effective with their artillery when in places that the germans were able to rain down indirect upon a static line such as in italy and particularly anzio the americans started to provide improvised roofs for their m-10s and wrote home to ordnance to please issue armored covers ordnance did indeed look into developing them and created armored roofs for all three of its vehicles although only the m18 and the m36 seem to have been officially approved for production note that the roofs were still to be sufficiently high as to allow to grew to see reasonably well while still obstructed so they're not confined to periscopes they were also high enough that they did not interfere with the loading process or the ammunition indirect fire was the primary concern for these armored covers but so was small arms in built up areas that it was expected these vehicles may be fighting in in europe as a result not only was the vehicle designed to resist artillery from the top but they went as far as to test the effects of small arms fired through the gap maybe ricocheting down off of from the top of the roof a special splash guard had to be installed which solved that problem that said the field troops seemed less worried by this latter problem because they don't see the roofs very much in europe by this time though the war was almost over so you will only really see the roofs on post-war m-36s the british apparently came to a similar conclusion with a roof with a gap developed for both archer and avenger the germans as mentioned gave jig panther pretty solid armor and the jagdpanzer 38t also had a roof but again they are on the receiving end of both effective artillery and effective airstrikes so it may well have been worth the hassle and the penalties so there you go that's why tank destroyers generally ended up looking the way that they did if you want to learn more at least from the american side feel free to buy the book can openers written by me if you haven't seen it already and otherwise i hope you found it generally interesting and informative and i will see you on the next one take care

Channel: The_Chieftain

Views: 130,970

Rating: 4.9690909 out of 5

Keywords: TD, Hellcat, M18, M10, Panzejaeger

Id: gz0GvmyQN80

Length: 24min 44sec (1484 seconds)

Published: Sat Oct 10 2020